Q10TYU - Campbell Biology

Question

Question: This computer model shows the four parts of ATP synthase. Each part consists of several polypeptide subunits (the structure in gray is still an area of active research). Using Figure 9.14 as a guide, label the rotor, stator, internal rod, and catalytic knob of this molecular motor.

Step-by-Step Solution

Answer

The parts of the ATP synthase in the computer model are the rotor, stator, internal rod, and catalytic knob. Each part has a definite function in the ATP synthase mechanism.

Step 1: ATP synthesis

The enzyme ATP synthase mediates the synthesis of ATP. The hydrogen is pumped out of the cells during the oxidative phosphorylation stage. The hydrogen ions are returned to the matrix again that phosphorylates the ADP with phosphate molecules, resulting in ATP formation. 

Step 2: ATP (Adenosine triphosphate)

ATP is a simple molecule that fulfills the energy demand of the body. These molecules are produced in the different stages of metabolic processes such as glycolysis, Kreb's cycle, and electron transport chain. The phosphorylation of ADP results in the formation of ATP.

Step 3: ATP synthase and its parts

The rotor is the rotating end that is found in attachment with the membrane. In this rotor, hydrogen ions get attached to the binding sites. It makes the rotor spin. 

The stator is the channel-like structure anchored in the membrane through which the hydrogen ions reach the rotor. The extension of the rod present in the rotor leads to the formation known as a catalytic knob. The internal rod is the connectivity between the rotor and catalytic knob.